Photo: Karen Thomas
Tip the barley into a pan of lightly salted simmering water and cook for about 25 minutes until tender. Meanwhile, slice the courgettes into quarters lengthways and cut the broccoli into short lengths, then steam both for 8-10 minutes until just tender but still vibrant and green; cool.
Mix the chilli, sesame oil, soy sauce, Thai fish sauce, tamarind paste (or lemon juice) and sugar in a cup.
Drain the barley, then tip into a mixing bowl, add the dressing and toss together; cool.
To serve, toss the courgettes and broccoli with the barley along with the peas (no need to cook them), watercress and herbs.